The invention relates to opto-electronic components, and, more particularly, to liquid crystal nematic substances for the control of the light transmission and for the display of figures, symbols and images. Furthermore it relates to liquid crystal 7-alkyl-perhydrophenanthren-2-carboxylic acids and esters, and to the method of making such compounds.
A very large number of chemical compounds are known to have liquid crystal nematic characteristics D. Demus. H. Demus and H. Zaschke, Fluessige Kristalle in Tabellen, VEB Deutscher Verlag fuer Grundstoffindustrie, 2. Auflage Leipzig 1976. None of these individual compounds, however have the required properties which are necessary for optimum use of the compounds as liquid crystals in opto-electronic components. For this reason, mixtures of several such liquid crystal compounds have been heretofore used in opto-electronic components.
The temperature ranges under which such mixtures can be used in commercial application are of particular importance. For example, clearing temperatures of 70.degree. and above, and working temperatures of -10.degree. C. and below are particularly desired. In addition, the cell switching times should not be excessively high at low temperatures.
Accordingly, it is an object of the present invention to provide novel nematic liquid crystal compounds which have operable temperature ranges indicating high clearing temperatures, low working temperatures and favorable switching times.
Another object of the invention is to provide new nematic liquid crystal 7-alkyl-perhydrophenanthren-2-carboxylic acids and esters thereof, compositions thereof, and a method for such production of the compounds.
Still another object of the invention is to provide an opto-electronic display which uses as a cell component a novel liquid crystal nematic 7-alkyl-perhydrophenanthren-2-carboxylic acid or ester compound as a nematic liquid crystal substance.